R=120;
C=33e-12;
tau=R*C;
fprintf('tau= %f ns \n', tau*1e9);
T=tau/100;
t=0:T:3*tau;
U(1)=0;
S=10;
for i=2 : length(t)
    U(i)=(S+U(i-1)*tau/T)/(1+tau/T);
end
fprintf('U= %f V \n', U(length(t)));
plot(t,U)